Leinster moved five points clear at the top of the Magners League but they made hard work of disposing of a second-string Ospreys outfit 26-15 at the RDS.
There was a try apiece for Leinster's starting back rowers - Shane Jennings, Jamie Heaslip and Stephen Keogh - during a promising first half.
And when livewire winger Luke Fitzgerald dived over for the bonus point try, with 30 minutes still left on the clock, there looked to be a lot more in the home side's tank.
But, driven on by replacement Filo Tiatia, the Ospreys dominated the closing stages and were unfortunate not to follow up on flanker Ben Lewis' 77th-minute try.
Had they done so, a losing bonus point was theirs and Leinster's victory - their fourth over the Welsh region in five games - would have been somewhat soured.
With Wales coach Warren Gatland and Ireland boss Eddie O'Sullivan both sitting in the stands, the players not only had league positions on their minds but also selection for the fast-approaching RBS 6 Nations.
And man of the match Heaslip certainly put his hand up for inclusion in O'Sullivan's plans.
There was also a notable return to form for Ireland captain Brian O'Driscoll, who looked to be over the worst of an ankle injury, and the fleet-footed Fitzgerald could just be the man to enliven a misfiring Irish back-line.
The 20-year-old was a menace throughout and, had Leinster shown more precision in attack, they would have safely pocketed their bonus point by half-time.
England Under-18 head coach John Fletcher insists his young side will be better for the experience after beating Italy in the bronze final to round out their 2015 Rugby Europe U18 Championship campaign in style.